EP0650540B1

EP0650540B1 - Baled waste paper pre-recycling treatment

Info

Publication number: EP0650540B1
Application number: EP19930908415
Authority: EP
Inventors: Ivar H. Stockel; Willard E. Carlson
Original assignee: Individual
Current assignee: Individual
Priority date: 1992-03-20
Filing date: 1993-03-18
Publication date: 2001-08-29
Anticipated expiration: 2013-03-18
Also published as: KR100247489B1; FI111017B; US5271805A; EP0650540A4; NO943471D0; DE69330677D1; NO943471L; US5496445A; WO1993019244A1; KR950701025A; AU665824B2; RU94041700A; NZ251559A; EP0650540A1; BR9306127A; AU3924493A; ATE204933T1; FI944341A; CA2132322A1; NO304701B1

Abstract

A method and apparatus for reclaiming cellulosic fibers from a bale containing waste papers, in which the bale is positioned in a treatment enclosure, and the enclosure is placed under a vacuum. A treating fluid is drawn into the enclosure, which penetrates the bale interior spaces, and produces a preferential swelling-of uncontaminated cellulosic fibers. After the treating fluid is withdrawn from the enclosure, a slurrying fluid is passed through the bale contents, to form a fiber-fluid suspension slurry.

Description

The present invention relates to a method and apparatus for a paper recycling process in which cellulosic fibers are recovered from a bale containing waste papers.
More particularly the present invention relates to a process of treating a bale containing waste papers, which contains a mixture of cellulosic fibers, contaminated cellulosic fibers and separated or freely dispersed contaminants.
The term contaminants, as used herein, means materials of a non-cellulose fiber character, such as wax, polymer coatings, foil coatings, inks, dirt, stones, etc. The present invention has wide applicability in the recycling of paper products, for reuse in making paper.
In existing processes for making paper, it is a common practice to use waste paper materials either alone or along with virgin pulp. The waste paper materials, recycled back into the papermaking method, commonly include, e.g., rejected paper stock in the plant, old corrugated containers, paper bags, newspapers, magazines, used paper containers of various types, office waste, mixed waste and old files. Some of these waste paper materials have coatings thereon that interfere with normal papermaking operations, e.g., wax coatings, impregnated wax, various plastic coatings, and aluminum foil coatings. Dirt, paper clips, wires, some inks and other contaminants associated with waste papers may also pose a problem.
Before the waste paper can be used in the manufacture of new paper, the cellulosic fiber content of the waste paper should preferably be separated from the contaminants. The separation method should be carried out in such a fashion so as to minimize degradation or damage to the cellulosic fibers, e.g., by cutting, shortening or weakening such fibers.
It is known to recycle waste paper products by mechanically breaking or tearing apart such products in a pulper. However, such action damages and adversely changes the physical characteristics of the fibers. Also, the pulper does not always completely separate contaminants from the cellulosic fibers. Another disadvantage is the fact that considerable energy is required to effect a desired separating action.
FR-2406022 discloses the concept of putting loose ie. separated, material in a sealed chamber, applying a vacuum, and introducing a debonding liquid.
An aim of the present invention is to provide both a method and apparatus for extracting relatively pure cellulosic fibers with desired strength potentials from bales containing waste paper having contaminated and uncontaminated cellulosic fibers therein. The term "relatively pure" cellulosic fibers is herein used to mean a close approximation of the original virgin pulp fibers whose cellulose content is known to vary from about sixty percent to about ninety-five percent.
According to the present invention there is provided a paper recycling process in which cellulosic fibers are recovered from waste paper material subjected to a fiber debonding treatment comprising submergence of the waste material in a fiber swelling and debonding liquid while confined in a closed chamber under a vacuum for a period sufficient to liquid impregnate the submerged waste material after which it is returned to an atmospheric pressure environment and subjected to fibrillation for separating out swollen and debonded cellulosic fibers, characterized in that said fiber debonding treatment comprises the steps of:
(a) positioning a bale form of waste material containing waste paper within the chamber;
(b) sealing the interior of said bale containing chamber from the atmosphere;
(c) establishing a vacuum within said sealed chamber;
(d) introducing sufficient fiber swelling and debonding liquid into said sealed chamber as submerges said bale;
(e) maintaining said bale within said sealed chamber under vacuum while submerged in said liquid for a period sufficient for cellulosic fibers of waste paper in said bale to sorb an amount of said liquid as establishes a debonding swelling to the degree that application of fibrillation to said liquid treated bale separates out said debonded swollen cellulosic fibers.
According to a further aspect of the present invention there is provided wetting impregnation apparatus for the wetting impregnation of cellulosic fiber containing material with a cellulosic fiber softening and swelling fluid in establishing a debonding swelling of the cellulosic fibers of said material comprising:
a chamber having an interior adapted to receive and contain said material therein and seal said chamber interior from the atmosphere,
means for establishing a vacuum pressure within said chamber interior and
means for introducing into and retaining in said chamber said softening and swelling fluid for a sufficient time as establishes said debonding swelling of said fibers, characterized in that said chamber comprises:
a base and a vertically displaceable hood having a top portion extending transversely of a columnar annular wall portion vertically depending below said hood top portion and cooperating with said base in defining said chamber when said hood is in a lowered position with the lower end of said annular hood wall in contact with said base and
means for vertically displacing said hood between said lowered position and a raised position in which said hood wall lower end is spaced above said base.
In one particular embodiment of the present invention, a bale containing waste paper is impregnated. by a treating fluid, e.g, a dilute solution of ammonium hydroxide, for a period of from about five to about sixty minutes. The basic solution causes the uncontaminated cellulosic fibers to preferentially swell and debond from each other, Contaminated fibers undergo swelling at a substantially reduced rate, because coatings on the contaminated fibers prevent the treating fluid or swelling agent from readily wetting the fibers. By subsequently adding water to the swollen fibers, it is possible to form a fiber-fluid suspension, or slurry, that can flow freely in a liquid-like fashion. It thus becomes possible to remove the cellulosic fibers from the contaminated fibers by draining or pumping the fiber-fluid slurry suspension away from contact or intimate association with the contaminants or contaminated fibers, i.e., the fibers bound up with other non-fiber substances such as polymer coatings, wax coatings, impregnations, etc.
Apparently, the cellulosic fibers in waste papers have bond strengths between fibers, which are reduced by swelling as compared with bond strengths with and between other associated materials such as polymer coatings, adhesives and foils. By keeping the cellulosic fibers in contact with the treating fluid for only a predetermined, limited time period, or time window, it is possible to preferentially swell and debond the uncontaminated cellulosic fibers from each other, while affecting to a much lesser extent the fiber to fiber bonding of contaminated fibers and the fiber to contaminant bonding.
In order for the method to work in an optimum fashion, the treating fluid should be brought into contact with all of the waste paper material at approximately the same time so that a major portion of the cellulosic fibers will be exposed to the treating fluid within an acceptable time window. If this is not the case, then some of the waste paper materials will be subjected to the treating fluid swelling treatment for a longer period than desired, while other waste paper materials will be subjected to the treating fluid swelling treatment for a shorter period than desired. In practice, it is rather difficult to achieve simultaneous contact between the treating fluid and all of the papers in a bale containing waste papers. The straps, twine or wire holding the bale together tend to keep the bale contents in close physical contact such that the treating fluid cannot easily or quickly penetrate through the bale outer surface into interior portions of the bale.
Even when the straps, twine or wires encircling the bale are broken, the waste papers are often adhered or stacked closely together such that the treating fluid has difficulty passing through from the exposed outer surfaces of the bale or bale fragments to the interior of the bale or bale fragments.
In order to ensure timely and approximately simultaneous contact of the treating fluid with all, or most of, the uncontaminated cellulosic fibers in a bale containing waste papers, the present invention contemplates that the entire bale will be located in a vacuum, or near vacuum, enclosure when the treating fluid is initially brought into contact with the bale. Due to the vacuum, i.e., sub-atmospheric condition, the treating fluid will tend to be rapidly drawn into very tiny crevices, or openings, in the bale, i.e., between adjacent sheets or layers. This condition of gas evacuation, or vacuum impregnation, will overcome such adverse factors as surface tension and gaseous pressure resistance so as to more quickly wet a substantial percentage of the cellulosic fibers in the bale.
The term "gaseous pressure resistance" is herein used to mean the resistance to flow offered by a mass of air trapped in a closed space. Air may be trapped within the bale for a period of time, thereby preventing rapid, or complete, penetration of the fluid into all parts of the bale. However, by placing the enclosure under vacuum before or during the treating fluid admission period, it is possible to eliminate or minimize the trapped air bubble phenomenon.
The present invention contemplates that the treating fluid will be in essentially laminar flow first and thereafter, in an essentially still, or stagnant, condition while it is in contact with the waste paper, so that any relative motion between the treating fluid and fibers does not damage the fibers or break contaminated papers and contaminants into small pieces that would be difficult to separate from the swollen fibers. The laminar and then stagnant condition also allow the treating fluid to remain in contact with the bale contents for the necessary time in order to penetrate and swell the uncontaminated cellulosic fibers.
The method of the present invention in some of the invention's embodiments also contemplates one or more enclosure reduction steps in order to break up the bale, drive the treating fluid into more intimate contact with the cellulose of the uncontaminated fibers and minimize the ratio of treating fluid to solids, i.e., paper. Thus, in the example of one of said embodiments, after the bale containing the waste papers has been placed into a closed treatment enclosure, a piston will be moved in a direction which will reduce the size of the enclosure. When the treating fluid is later fed, or drawn, into the treatment enclosure under vacuum, the treating fluid will occupy most of the void spaces to achieve a high solid-to-fluid volume ratio of at least 20 percent within the bale or the bale fragments. This action will reduce the treating fluid requirement. Depending upon the extent of size reduction of the enclosure, and upon the attachment of breaker bars to the face of the piston, this action may also break up the bale. In the example of another of said embodiments, after the bale containing waste papers has been placed into a closed treatment enclosure and the treating fluid has been fed or drawn into the treatment enclosure, under vacuum, and the treating fluid has occupied most of the void spaces, a piston will be moved in a direction which will reduce the size of the enclosure. This action will force treating fluid deeper into the smallest voids inside the bale as well as forcing some of the treating fluid back out of the enclosure. This action may also break up the bale under circumstances described in the previous embodiment.
The present invention contemplates a two-stage process wherein, during the first stage, a treating fluid, i.e., a swelling agent, is brought into contact with the waste paper solids. When the cellulosic fibers have swollen to a desired amount, the treating fluid is withdrawn from the treating enclosure. The second stage involves passing a fluid, usually water, into and through the bale solids, forming a fiber-fluid slurry. During this operation, there may be an agitation of the bale solids for at least part of the fluid-solids contact period. The agitation in this second stage is considered to be helpful in separating the uncontaminated fibers from associated clumps, or pieces of contaminated waste paper materials and other contaminants.
The second stage produces a fiber-fluid slurry that can be pumped, or otherwise separated, from the various contaminants.
The present invention will now be further described, by way of example, with reference to the accompanying drawings, in which:-
Figure 1 is a graph showing the relationship between soaking time and tensile strength loss for selected waste paper materials soaked in water containing two percent ammonia.
Figures 2 through 5 are schematic views of an apparatus that can be used in practice of the present invention. The different views illustrate the apparatus at different stages of a method for reclaiming cellulosic fibers from waste papers.
Figure 6 is a schematic view of another apparatus embodying features of the present invention.
Figure 7 is an enlarged view of the apparatus depicted in Figures 2 through 5.
Figure 8 is an enlarged sectional view of a retractable agitator mechanism used in the Figure 7 apparatus.

DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE PRESENT INVENTION

Figure 1 is a graph showing the relationship between soaking time and tensile strength loss for selected waste paper materials soaked in water containing two percent ammonia.
Figure 1 is a graph depicting tensile strength loss (percentage) for waste paper materials soaked in a two percent ammonia solution. Curve 6 is taken for waste papers in the form of uncoated double-lined Kraft corrugated cuttings and uncoated old corrugated containers. Curve 7 is taken for wax dipped corrugated containers and curtain coated corrugated containers. Curve 6 may be considered to represent uncontaminated waste papers, whereas curve 7 may be considered to represent contaminated waste papers. It will be seen that the time required for the materials to lose their tensile strength is much shorter for the curve 6 materials as compared to the curve 7 materials.
Loss of bonding strength in the cellulosic fibers occurs as the treating fluid causes the fibers to swell and undergo a debonding action. It will be seen from the graph that the uncontaminated cellulosic fibers, i.e., curve 6, have lost a substantial percentage of the original tensile strength after about twenty minutes' soak time, whereas the contaminated cellulosic fibers, i.e., curve 7, still retain a substantial percentage of the original tensile strength after the same soak time. Soaking in a basic treating fluid, such as ammonia, for a predetermined time period, e.g., twenty minutes, represents a method that can be used to separate uncontaminated waste paper fibers from contaminated, e.g., certain coated and impregnated, etc., waste paper fibers.
Figures 2 through 5 are schematic views of an apparatus that can be used in practice of the present invention. The different views illustrate the apparatus at different stages of a method for reclaiming cellulosic fibers from waste papers.
One or more bales 10, containing waste paper bound with wires or straps is/are moved onto a base 11 for treatment. Reference to "bale" or "bales" herein, in either case, may indicate either a singular bale or a plurality of bales. A treating enclosure 12 comprises base 11 and a raised hood or housing 14. After the bale 10 is positioned on base 11, the hood 14 is lowered onto the base 11 as shown in Figure 3. Hood 14 comprises an upright tubular cylinder 13 and a piston 15. However, hood or housing 14 may also, in certain embodiments, be comprised of a not fully rigid structure, where desirable. In the lowered position of the hood 14, piston 15 can be moved vertically within the cylinder 13.
A reservoir of treating fluid 13 is connected to base 11 via a fluid line 35 containing a valve 37. By reducing the pressure within enclosure 12, it is possible to draw treating fluid from treating fluid reservoir 33 through line 35 and into the enclosure 12. Various treating fluids can be used in this invention, e.g., sodium hydroxide, sodium carbonate, ammonia, sodium hypochlorite, etc. The treating fluid has as its primary purpose the controlled swelling and debonding of the uncontaminated fibers in bale 10 without similarly swelling or attacking the coated fibers and contaminants such as plastics, adhesives, stones, paper clips, etc., within the desired time window. Additionally, other fluids having other than swelling and debonding capabilities may also be employed, either in the treating fluid stage or subsequent stages.
With bale 10 within enclosure 12, the internal volume of enclosure 12 is reduced to approximately the value depicted in Figure 4. Thus, piston 15 can be moved vertically downwardly within cylinder 13 from the Figure 3 position to the Figure 4 position. The purpose for moving the piston 15 downwardly within cylinder 13 is to break the bindings that hold the bale 10 together, and also to eliminate excess volume within the enclosure 12 and, further, to deform and break apart the bale 10 and to further force the treating fluid into the smallest voids within the bale. Piston 15 is equipped with a number of radially-oriented breaker bars 56. As the piston 15 descends within cylinder 13, the breaker bars 56 break the wires or straps that bind the bale 10 together. The descending piston 15 also causes the bale 10 to at least partially break apart within the enclosure 12.
A vacuum means 39, which may be either a vacuum pump or other vacuum means, is located to draw air gases out of enclosure 12, thereby reducing the space within the enclosure 12 to a near-vacuum condition. Thereafter, valve 37 can be opened so that treating fluid is drawn under vacuum from treating fluid reservoir 33 through line 35 and into the enclosure 12. The treating fluid quickly penetrates the small pores and crevices within bale 10. The step of placing the enclosure 12 under a vacuum can be performed before, during or after the step of lowering piston 15 to the Figure 4 position. In the illustrated embodiment, the treating fluid is admitted to the enclosure 12 after the piston is in the Figure 4 position.
The treating fluid is permitted to remain in the enclosure 12 in contact with waste paper materials of bale 10 for sufficient time to ensure a preferential swelling and debonding of the uncontaminated fibers in bale 10. The period of sufficient time depends upon the grade of waste paper being treated and upon the temperature and chemical composition of the treating fluid. In the case of old corrugated containers being treated with a two percent ammonia solution, a period of about twenty minutes is usually sufficient. When the uncontaminated cellulosic fibers have sufficiently swelled, the excess treating fluid is allowed to return through line 35 into fluid reservoir 33. This may be accomplished by removing the vacuum force, e.g., by venting the enclosure 12 to the ambient atmosphere, and opening valve 37. Also, piston 15 can be lowered an additional amount from its Figure 4 position in order to exert a pressing or squeezing action on the bale contents or components, aiding in moving the excess treating fluid down into the fluid reservoir 33. When the excess treating fluid has been returned to fluid reservoir 33, valve 37 is ther closed. Make-up treating fluid is added to reservoir 33 to maintain the amount and chemical strength of the treating fluid. It should also be noted that in appropriate circumstances, more than one treating fluid may be applied to the bale contents, either sequentially or at the same time.
Figure 5 illustrates the apparatus in position for removing the swollen uncontaminated cellulosic fibers from enclosure 12. Three or more horizontal rows of high pressure fluid nozzles 65 are arranged in the wall of cylinder 13 to spray jets of a fluid, e.g., water, into the enclosure 12. The number and location of nozzles 65 can be varied as desired. However, in a typical application, there might be a total of about fifteen nozzles 65, arranged with five nozzles 65, in each of the three rows. The nozzles 65 are oriented to spray water or other fluid generally tangential in direction, and not necessarily directly toward the central axis. A pump 38 is provided in this embodiment of the apparatus to supply pressurized water to the various nozzles 65.
Cylinder wall 13 is of hollow construction, comprising an outer imperforate casing 41 and an inner perforated liner 43. A hollow annular space 46 is defined between casing 41 and perforated liner 43. Annular space 46 communicates with a ring of ports (not shown), in base 11, that then connect through a three-way valve (not shown) with piping systems 90 and 35. Pump 91 draws a fiber-fluid slurry from annular space 46 through piping system 90.
In overall operation, in the second stage, water (fluid) is fed into the enclosure 12 through nozzles 65. The water entrains the swollen cellulosic fibers to form a fiber-water (fluid) slurry. Pump 91 draws the fiber-water slurry out of the enclosure 12 through a path which comprises the perforations (openings) in liner 43, annular space 46 and base 11, and said three-way valve (not shown), and the piping system 90. The perforations in liner 43 are sized to retain most of the contaminants and contaminated fibers within enclosure 12. The fiber-water (fluid) slurry, possibly containing some contaminants, may then be passed through a deflaker 93, a hydrocyclone 95, and a thickener 97 to remove any undesired particulates and to provide a fiber-water slurry of desired fiber content. Water, removed by thickener 97, can be returned (recycled) from the thickener 97, to pump 38 via a water return line 98.
The operation of the Figure 5 apparatus may be somewhat improved, if desired, by including within the apparatus an agitating mechanism, depicted as 69. During the first stage of the operation, as represented by Figures 2 through 4, the agitating mechanism 69 is in a retracted position located generally below enclosure 12. During the second stage, as represented in Figure 5, the agitating mechanism 69 is elevated so that it extends within the contents of the disintegrated bale 10. A power mechanism (not shown here) is used to move the agitating mechanism 69 between its two positions. In its elevated position, the agitating mechanism 69 is adapted to rotate around its axis in order to agitate and slush the softened and swollen fibrous materials in the fiber-fluid slurry. Arms 87 extend from the post portion of the agitator mechanism 69 to perform an agitating function. Arms 87 and the supporting post also tend to attract and collect any ropes, strings, wires or other contaminants that might tend to blind the perforations in liner 43.
After pump 91 has pumped a sufficient amount of fiber-water slurry out of enclosure 12, the enclosure 12 is drained and the agitator mechanism 69 is returned to its retracted position. Hood 14 may then be raised to the Figure 2 position and contaminants swept off, or otherwise removed from base 11, to reset the apparatus for reception of another bale 10, or bales 10, containing waste paper materials.
Figure 6 is a schematic view of another apparatus embodying features of the present invention.
In this embodiment, cylinder 13 is a single annular wall rather than a double wall construction, as earlier described. Hood structure 14 is raisable and lowerable, as earlier described, whereby the bale 10 of waste paper is positionable within the defined enclosure 12. After the enclosure has been placed under a vacuum via a vacuum means, such as pump 39, etc., the treating fluid is drawn from reservoir 33 by opening valve 37.
The treating fluid is allowed to remain in the enclosure for a sufficient time, as discussed above, to produce the necessary swelling of the cellulosic fibers, the enclosure is then vented, after which valve 37 is then opened to drain the treating fluid back into reservoir 33. The method up to this point is similar to the method as described with the apparatus shown in Figures 2 through 5.
In this embodiment, fluid ports are formed in base 11 and piston 15 whereby pressurized fluid (water) can also be supplied through line 99 to aid in disintegration of the bale 10 components. The action of the water jets produced here is similar to that produced by the aforementioned nozzles 65, except that during the disintegration period, in this embodiment, the enclosure may be in a closed position, and the water may not flow out of the enclosure.
At the conclusion of the disintegration period or before, a valve 100 is opened to enable the fiber-water (fluid) slurry to gravitationally flow from the enclosure into a sump 101. A basket 102 is positioned within, or above, the sump 101, to receive the bale contents still remaining in the enclosure. Then, hood 14 is raised and the bale contents plowed, or otherwise transferred, to the basket 102. The bottom wall of the basket 102 is also perforated.
With the loaded basket 102 positioned above sump 101, water is pumped from source 103 by a pump 108 into a shower system 104 located above the basket 102. Water flushes downwardly from the shower system 104 through the contents in basket 102 to carry cellulosic fibers into sump 101. The perforations in the basket 102 are sized so that most of the contaminants are retained in the basket 102.
The fiber-water liquid slurry accumulated in sump 101 can then be subjected to various treatments to purify and condition it for use in papermaking operations. As shown in Figure 6, the fiber-water slurry may then be passed through a thickener 105 to remove excess water from the slurry. The fiber product exits through a line 107 while water removed by the thickener 105 is returned to pump 108 via line 109.
Figures 7 and 8 illustrate some structural features of the apparatus in greater detail.
Figure 7 is an enlarged view of the apparatus depicted in Figures 2 through 5.
Figure 8 is an enlarged view of a retractable agitator mechanism used in the Figure 7 apparatus.
Referring now to Figure 7 which shows in greater detail features of the Figures 2 through 5 apparatus, the following is an expanded disclosure. In Figure 7, there is shown a mechanism for raising or lowering hood structure 14. Multiple fluid cylinders 17 have piston rods 19 connected to vertical reinforcement bars 21 attached to wall 13 of the hood structure 14. The number of fluid cylinders can be varied, e.g., typically, four cylinders can be used. Each reinforcement bar 21 may have any desired cross section suited to its reinforcement function, e.g., a square, hollow tubular configuration, an H-shaped cross section or a channel cross section, etc. Simultaneous introduction of pressure fluid into the lower end of each fluid cylinder 17 raises hood 14 to a loading position, permitting insertion of bale 10 into the treatment space defined by enclosure 12. By pressurizing the upper end of each cylinder 17, hood 14 is brought downwardly to the closed position as shown in Figure 7.
Piston 15 is connected to annular wall 13 via a rolling or folding diaphragm 22, sometimes known as a bellofram. The piston 15 is shown in an elevated position at the upper end of annular wall 13. However, the piston 15 is designed to be moved downwardly within wall 13 to reduce the size of the treatment enclosure 12. The piston 15 is suspended within wall 13 by means of four fluid cylinders 23. Each fluid cylinder 23 has its piston portion 25 attached to an associated upright reinforcement bar 21 and its cylinder portion attached to piston 15.
Proper linear guidance of the piston 15 can be achieved by providing a guide channel 27 partially surrounding the fluid cylinder 23. A cooperating guide roller means 29 is mounted between two spaced arms 31 that extend from bar 21 across guide channel 27. As the four fluid cylinders 23 power piston 15 downwardly within wall 13, each guide channel 27 is guided by the associated guide roller means 29 and arm structure 31. It is noted that each fluid cylinder 23 is a double-acting cylinder.
The treating fluid or swelling fluid may be stored in a reservoir (not shown) located below base 11. The treating fluid may be at room temperature or heated. Heating of the treated liquid shortens the treatment or swelling, cycle time and also increases the cellulosic fiber yield. However, some contaminants such as wax, etc., melt or otherwise go into suspension at temperatures of about 120 degrees Fahrenheit. Therefore, lower temperatures of the treating fluids are preferred. For safety reasons, in those instances where it may not be prudent to pump, or otherwise violently spray, hazardous treating and other fluids, e.g, hot, caustic solutions, etc., the methods herein utilize liquid flow, resulting from either gravity or differences in relative pressures, i.e., vacuum suction or the like.
As shown in Figure 7, a treating fluid supply line 35 leads from the treating fluid reservoir (not shown) to base 11 of the treatment enclosure. A shut-off valve 37 is provided in the supply line 35 to control or stop the treating fluid flow. The treating fluid may be admitted to and withdrawn from enclosure 12 through a plurality of ports 32 formed, in part, in base 11.
Annular wall 13 is a hollow wall construction comprising an outer annular casing 41 and an inner rigid liner 43, spaced from annular casing 41, to define an annular hollow space 46 therebetween. Apertured bulkheads 47 interconnect casing 41 and inner liner 43 to rigidify the wall 13 structure against collapse under the liquid and vacuum loadings thereon.
Base 11 has an annular internal flow duct 49 that interconnects with annular space 46 via a ring of regularly spaced ports 51. Each port 51 should have an appropriate diameter to permit relatively unimpeded fluid flow between annular space 46 and duct 49. Cellulosic fiber suspension is withdrawn from and treating fluid may be admitted to and withdrawn from the apparatus by allowing flow to and/or from annular space 46, through ports 51, into or out of annular duct 49. Annular duct 49 is connected through a three-way valve, or its equivalent (not shown), to the aforementioned fluid supply line 35 or fluid return 90 at one or more points along duct 49.
Treatment enclosure 12 is defined by the inner surface of annular liner 43. The liner 43 has a large multiplicity of ports 53 extending therethrough at regularly spaced points along the liner 43 inner surface. Each port 53 has a diameter measuring from about one-quarter inch up to about two inches, which is of sufficient size to pass the fibrous fluid slurry produced in the treatment enclosure 12, but which is insufficient to pass most contaminants such as contaminated papers, coated papers, pieces of foil, plastics, film, etc. The spacing between ports 53 can vary within rather large limits, depending upon hole size, waste paper grade, etc., and established strength and stiffness guidelines, as long as there is a large multiplicity of flow paths for the treating fluid and fibrous suspension.
Before, during or after the treating fluid is initially introduced to the treating enclosure 12, via ports 32, in base 11, and via ports 53, in annular liner 43, piston 15 is lowered within wall 13 by actuation of cylinders 23. There are preferably four or more vertical breaker bars 56 mounted on the undersurface of piston 15. The breaker bars 56 are preferably arranged in a radial pattern, i.e, on radial lines generated from the piston axis.
As piston 15 is powered downwardly within annular wall 13, bars 56 exert fracturing forces on the straps or wires that are used to hold bale 10 together. Additionally, the face of the piston 15 exerts a downward force on the bale 10. As a result, the straps or wires break such that the contents of bale 10 can collapse outwardly toward liner wall 43 and downwardly toward base 11.
Before, during or after the downward stroke of piston 15, a vacuum means or, in this case, vacuum pump 39, is operated to substantially evacuate the air remaining in the treatment enclosure 12 and bale contents 10. Although a motor-operated pump 39 is shown herein as the vacuum means employed, it should be understood that other types of vacuum-producing devices can be used, e.g., an aspirator, a vacuum accumulator, etc. The evacuation of air from the enclosure 12 provides a sub-atmospheric condition within the treatment enclosure 12 relative to the external atmospheric pressure.
When valve 37 is opened, the three-way valve (not shown) is set to connect line 35 to annular duct 49, and the treating fluid flows from the reservoir upwardly in this embodiment through fluid line 35, into the treatment enclosure 12, via ports 32 and 53. The reduced pressure in the treatment enclosure 12 also draws the treating fluid into the tiny voids and crevices in the bale 10, thereby quickly bringing the treating fluid into essentially simultaneous contact with all interior surfaces of the bale constituent layers. Figure 7 shows three fluid nozzles 65 arranged one above the other. Each nozzle 65 has a horizontal trajectory going radically toward the chamber central axis, or at an acute angle to a radial line designed to promote a swirl motion. In this embodiment, there are actually three rows of nozzles 65 with four or five nozzles 65 in each row, resulting in a total of twelve or fifteen nozzles 65. Each nozzle 65 has a horizontal trajectory angled toward the chamber central axis. However, other configurations of nozzle 65 and number of nozzles 65 are also envisioned.
The bank of nozzles 65 is connected to a motor-operated pump 38, shown in Figure 5, that provides the entire supply of fluid, usually water, for the second stage in the process.
A mechanical agitation mechanism 69, shown fragmentarily in Figure 7, is provided for applying an agitating force to the contents or components of the broken bale 10, during the second stage of the process. During the first stage, i.e., the treating fluid stage, the agitation mechanism 69 is retracted into or below base 11 to assume an inoperative standby condition.
Figure 8 is an enlarged sectional view of the agitator mechanism 69 used in the apparatus of Figure 7, as well as the apparatus of Figures 2 through 5. As seen in Figure 8, the agitating mechanism comprises a vertical post 71 having a rotary support in a sleeve bearing 73 which is carried on a platform 75. Electric motor 77 drives a spur gear 79 which meshes a second gear 81, carried by a post 71. The post 71 is thus powered for rotary motion around its axis. As fragmentarily shown in Figure 7, platform 75 is connected to the piston portion of the fluid cylinder 83 (shown in Figure 7). The fluid cylinder 83 can be actuated to raise or lower post 71 between the two positions, i.e., the operating or retracted standby positions.
In order to assist the post 71 in better penetrating the broken bale 10, the upper end of the post 71 may have a conical shape. Also, a high pressure fluid (water) nozzle 85 may be located on the upper end of the post 71. Pressurized fluid, usually water, is supplied to the nozzle 85 through a small tube or conduit extending vertically through the post 71. The nozzle 85 trajectory is directly up such that the nozzle 85 output stream tends to burrow one or more holes through the bale 10 as the post is raised by fluid cylinder 83.
As also shown in Figure 8, post 71 carries two swingable agitator arms or striker elements 87. As the post 71 begins to rotate, the striker elements 87 are thrown outwardly from the post 71 by centrifugal action. The agitator arms 87 act as a "ragger" impeller for agglomerating and collecting contaminants such as wires, strings, films, etc., as well as an agitator to accelerate, or further increase, the bale breakage method and fiber dispersion. After the second stage of the method is complete, the agitator mechanism 69 is lowered, retracted into and/or below base 11. The agitator arms 87 fold into post 71 during the downward motion of the post 71. Spring-urged bullet latches may be carried on the free ends of arms 87 in order to hold them in their folded positions, while the agitator mechanism 69 is in its retracted condition.
The drawings contained herein necessarily depict specific embodiments of the apparatus useful in practice of the present invention. However, it will also be appreciated by those skilled in the arts pertaining thereto that the present invention can be practiced in various forms and configurations.
Further, the detailed description of the preferred embodiments of the present invention is presented for purposes of clarity of understanding only, and no unnecessary limitations should be understood or implied therefrom. Finally, all mechanical and functional equivalents to the above which may be obvious to those skilled in the arts pertaining thereto are deemed to be encompassed within the claims of the present invention.

Claims

A paper recycling process in which cellulosic fibers are recovered from waste paper material subjected to a fiber debonding treatment comprising submergence of the waste material in a fiber swelling and debonding liquid while confined in a closed chamber (12) under a vacuum for a period sufficient to liquid impregnate the submerged waste material after which it is returned to an atmospheric pressure environment and subjected to fibrillation for separating out swollen and debonded cellulosic fibers, characterized in that said fiber debonding treatment comprises the steps of:

(a) positioning a bale form (10) of waste material containing waste paper within the chamber (12);

(b) sealing the interior of said bale containing chamber (12) from the atmosphere;

(c) establishing a vacuum within said sealed chamber (12);

(d) introducing sufficient fiber swelling and debonding liquid into said sealed chamber (12) as submerges said bale (10);

(e) maintaining said bale (10) within said sealed chamber (12) under vacuum while submerged in said liquid for a period sufficient for cellulosic fibers of waste paper in said bale (10) to sorb an amount of said liquid as establishes a debonding swelling to the degree that application of fibrillation to said liquid treated bale (10) separates out said debonded swollen cellulosic fibers.
A process as claimed in claim 1, in which non-sorbed fiber swelling and debonding liquid is drained from said chamber (12) upon completion of step (e) of said fiber debonding treatment and said fiber separation fibrillation comprises passing a fiber suspension liquid through said liquid treated bale (10) contained within said chamber (12) for forming a slurry of cellulosic fibers suspended in said fiber suspension liquid.
A process as claimed in claim 2, in which said fibrillation comprises directing high velocity jets of said fiber suspension fluid into said liquid treated bale (10) in forming said slurry.
A process as claimed in claim 3, in which said slurry is removed from said chamber (12) through a plurality of apertures in said chamber (12) sized to restrict passage therethrough to slurry containing small particles of cellulosic fibers.
A process as claimed in any one of claims 1 to 4, in which a compressive force is established on said bale (10) following any one of steps (a) through (e) of said fiber debonding treatment.
Wetting impregnation apparatus for the wetting impregnation of cellulosic fiber containing material with a cellulosic fiber softening and swelling fluid in establishing a debonding swelling of the cellulosic fibers of said material comprising:

a chamber (12) having an interior adapted to receive and contain said material therein and seal said chamber (12) interior from the atmosphere,

means (39) for establishing a vacuum pressure within said chamber (12) interior and

means (35,37) for introducing into and retaining in said chamber (12) said softening and swelling fluid for a sufficient time as establishes said debonding swelling of said fibers,

characterized in that said chamber (12) comprises:

a base (11) and a vertically displaceable hood (14) having a top portion (15) extending transversely of a columnar annular wall portion (13) vertically depending below said hood top portion (15) and cooperating with said base (11) in defining said chamber (12) when said hood (14) is in a lowered position with the lower end of said annular hood wall (13) in contact with said base (11) and

means (17,19,21) for vertically displacing said hood (14) between said lowered position and a raised position in which said hood wall lower end is spaced above said base (11).
Apparatus as claimed in claim 6, in which at least a portion of said hood top portion (15) is mounted for movement within and lengthwise of said hood wall portion (15) between a raised position and a lowered position in pressing contact with contents of said chamber (12), and said chamber (12) includes means (23,25,27,29,31) for moving said hood top portion (15) between said raised and lowered positions.
Apparatus as claimed in either of claims 6 and 7 in which said apparatus additionally includes an agitator unit comprising:

a mixer (69) supported to be moveable between a retracted position below said base (11) and an operating position projecting upwardly through said base (11) into the interior of said chamber (12),

said mixer (69) having a post (71) rotatable about its axis supporting retractable striker arms (87) pivotally mounted on an upper portion of said post (71) for rotation between a position housed within said post (71) and an extended position extended outwardly of said post (71),

means (77,79,81) for rotating said post (71) about its axis and

means (83) for establishing movement of said mixer (69) between said retracted and operating positions.